Carbureter.



H. J. MIDDLETON.

CARBURETER. APPLICATION man SEPT-22. me.

Patented Oct. 22, 1918,

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HOWARD J. MIDDLETON, F TOLE DO, OHIO, ASSIG-NOB.

- MANTHEY, 0F TOLEDO, OHIO.

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Specification of Letters Patent.

Patented first 22, 1918,.

Application filed September 22, 1916. Serial Elm-121,567.

To all whom it may concern. 3

Be it known that I, HOWARD J. IVIIDDLETDN, a citizen of the United States, and a resident ofToledo, in the county of Lucas and State of Ohio, have invented a certain new and useful (Jai-bureter; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawing, and to the characters of reference marked thereon, which form a part of th s specification.

' This invention relates to carburetors for use in connection with internal combustion engines. e

The object of my invention is the provb sion, in a carburcter, of improved means for controlling the admission of air to the mixing chamber thereof, wherehj' an in creased volume of air is admitted to said chamber when the throttle has been opened a predetermined extent.

The invention is fully described in the following" specification, and while, in its broader aspect, it is capable of embodiment in numerous forms, a preferred embodiment thereof is illustrated in the accompanying drawing, the carbureter being shown in cen tral longitudinal section therein,

Referring to the drawing, 3. designates the using forming the mixing chamber 2, and having its lower end projecting, in present instance, down through the howl'fl which forms the float chamber of the carburetor and has its upper end provided with an outlet passage 4 and flanged as a vide a coupling member to ada; to be sccured to the customary nani't if oft-an en- ,gine. A throttle valve 5 of mounted in the outlet passage t and fixed to a shaft 6 for turning movements therinvith. 7 designates a control jccts transversely from one end of the shaft (3 without the casino; 1. The casing l is flanged adjacent to its middle as at 8 to adapt it to seat over and close the top of the bowl 3 and the lower end of said casing is provided with a tubular extension i), which is threaded through a central bottom opening in the bowl 3. The lower end of he e. tension 5) threads without the bowl bottom into a horn l0 and serves to hold said horn lirn'ily to the bottom of the bowl. I The horn butterfly form is arm which fixedly pro-- in;1 through the valve is increased forms an air intake passage 11, which opens to the atmosphere at the outer end of the horn and communicates at its inner end with the lower end of the extension 9. The portion or the casing 1 which forms the mixing chamber 2 above the extension 9 flares outward from said extension and then inward, to the portion of the casingdorming the passage 14 provided in a portion of the horn 10 and through the bottom of the bowl 3. The nozzle 12 has a restricted discharge orifice at its upper end and preferably has its upper end in cup form and flaring outward from the discharge orifice, as shown. Thenozzle 12 is preferably such as length of the to dispose its upper end adjacent to or within the lower end portion of the mixing chamher 2.

A choke-valve 15 for controlling the air supply to the mixing chamber 2 from the air supply conduit ii. is mounted. in the extension 9, having a longitudinally sliding fit therein, being partially graded in its movement by the guide ribs in the chamher :2. This valve is prcie'rab t a long to extend from the lower end of the eXten sion 9 to a point above the disc end or" the nozzle 12 and is provided tudi nally tnerethrough with a central passage 16, which is gradually re diameter upward from its lower cut to a point at the side of the discharge end of the nozzle, when the valve is in normal lowered position, and thence preferably liar-ed out ward, as shosvn. The restricted portion 01" the valve passage 16 is slightly larger than the flared end of the nozzle 12 to permit the passage of a small stream of air upward through the valve around the discl urge end of the nozzle when the nozzle is within the restricted portion ofthe valve 31a sa will be understood that as the valve from normal position the volume o;

portion to the increase in the the nozzle end and the wall 1 passage, due to the taper portion or the pas The valve 15 is connected by a rod 17 to the throttle valve 5 at the edge thereof Which moves upward when the throttle is opened, thereby causing the throttle valve 5 and air valve 15 to have opening and closing movements in unison.

It is important for economy in fuel consumption and for improved. running condi; 'tions of a motor to admit an increased volume of air to the mixing chamber when the throttle has been opened a predetermined extent. This is accomplished, in the present instance, by providing the air valve 15 with a plurality of laterally extending ports 18. which open outii'ard from the passage 16 transversely of its axis, and are normally closed at their outer ends by the casing extension 9. These ports are so arranged With respect to the length of the valve and the lower upwardly flaring end, of the mixing chamber Qthat they are uncovered to the lower end portion of the mixing chamber when the valve has been raised a predetermined extent, thereby admitting a greater volume of air.into the mixing chamber 2 from the air supply passage ll, and is permitted-to pass into the chamber 2 through i the valve passage 16 around the nozzle. It

is evident that the volume of air flowing into thechamher 2 'from the ports 18 is determined by the extent oi uncovering of said ports. it is preferable to make some of the ports 18 longer than the others lengthwise oi the valve so that a greater upward r; ment or the vali 'e will be permitted beiore the ports entirely uncovered.

I wish it understood that my invention is not limited to any specific construction, arrangement, or form of the parts, it is capable of numerous modifications Without departing from the spirit thereof as defined in the claim.

Having thus described my invention, what I claim as new and desire to secure by Let ters Patent, is,

In a carburetor, a casing having an elongated passage therethrough in communication at its lower end with the atmosphere and being conieall y enlarged and then gradually restricted intermediate its ends to form a mixing chamber, the walls of said chamber being formed With longitudinally extending guide ribs, an air valve fitted in said passage below said chamber and guided by the passage Wall and said ribs for longitudinal sliding movements therein, said valve having an air passage longitudinally therethrough 'which gradually reduces in size from its lowerto near its upper end, and also having air discharge ports of vary ing verticalv'idth extending laterally from said air passage below the portion thereof which is reduced to the greatest extent and adapted to uncover to the lower portion of the mixing chamber when the valve has been raised a predetermined extent, means for controlling the movements of said valve, and liquid fuel discharging nozzle extending up into said valve passage,

In testimony whereof, I have hereunto signed my name to this specification,

I-lOiVARD J. llfilD'DliEiit ll. 

